The present invention concerns a key for the input of data with a selective symbol display and a keyboard using this key.
A key of the diaphragm type is known, which, in the lower part thereof, comprises a liquid crystal display and, above the display, a flixible transparent film separated from the display by a suitable spacer. Two wires which are respectively deposited on the upper part of the display and on the lower part of the transparent film can come into contact to generate an input signal as a result of the transparent film being operated by means of a finger. Selective activation of the various areas permits the key to display a plurality of symbols. On the other hand, a key of that type has rather limited reliability and ergonomic characteristics and is not suitable in particular for keyboard operation for typewriters in which an error in finger operation causes incorrect characters to be printed. Furthermore, the use of a key of that type in a keyboard requires a large number of conductors for activation of the various areas, giving rise to major problems in regard to space and reliability.